The present invention relates in general to a method for controlling a drawing apparatus, a drawing apparatus, and a waveform recording apparatus. More particularly, the present invention relates to a method of controlling drawing apparatus, a drawing apparatus, and a waveform recording apparatus that can draw figures or waveforms to match to the ruled lines of a graph paper.
A typical example of drawing apparatus is a plotter, which treats the coordinate Zc in an input drawing command as the coordinate Zp in the plotter coordinate system P, moves the movable drawing head two-dimensionally to the coordinate Zp, and draws a figure on paper using devices such as a pen. White paper is generally used in a plotter.
Another example of drawing apparatus is a waveform recording apparatus, which treats a coordinate Zc in an input drawing command as a coordinate Zp in the coordinate system P of the waveform recording apparatus, moves the movable drawing head one-dimensionally to the coordinate Zp, and draws a waveform on paper traveling in a direction perpendicular to movement of a head using devices such as a pen. Generally, graph paper, which is printed with ruled lines, is used in a waveform recording apparatus.
A plotter generally draws figures on white paper; in such cases, it is not possible to read the dimensions of the figure drawn by a plotter. A graph paper may be used instead of white paper, but if a graph paper, has contracted or expanded because of humidity, the lines of the figure drawn will be offset from the ruled lines of the graph paper. In practice, only approximate dimensions can be read.
On the other hand, waveforms are generally drawn on graph paper in a waveform recording apparatus, but because of the offset between the ruled lines of the graph paper and the lines of the drawn waveform, only approximate values can be read in this case also.